Brihat Parashara Hora Shastra
सुतेशे रिपुभावस्थे षष्ठेशे गुरुसंयुते । व्ययेशे लग्नभावस्थे तस्य पुत्रो रिपुर्भवेत् ॥ २७॥
INIMICAL SONS. One‟s own sons will be his enemies, if Putr Lord is in Ari, while Ari Lord is with Guru. Simultaneously Vyaya Lord should be in Lagn.
english translation
suteze ripubhAvasthe SaSTheze gurusaMyute । vyayeze lagnabhAvasthe tasya putro ripurbhavet ॥ 27॥
hk transliteration by Sanscript